Process for reducing and desulfurizing refractory ores.



0. A. CASE. PROCESS FOR REDUCING AND DESULFURIZING REFRACTORY ORES.

' APPLICATION FILED 0ST. 11, 1009 g g 5 Y Patented. Jan. 24, 1911.

2 SHEETS-SHEET 1.

2 SHEETS-SHEET I i H 0. A. CASE. PROCESS FOR REDUCING AND DESULFURIZING REFRACTORY ORES. I 4

APPLICATION FILED OCT 11, 1909. 98$,Q45, Patented Jan. 24, 1911.

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m 5 h, H \%w Y .4 MW W 0 TNT CHARLES ANDERSON CASE, OF NEW YORK N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS,

TO ORE DESULPHURIZATION COMPANY A CORPORATION OF NEW YORK.

PROCESS FOR REDI TCING AND DESULFURIZING REFRACTORY QRES.

To all whom 'it may concern:

Be it known that I, CHARLES ANDERSON CASE, a citizen of the United States, and a resident of the borough of Manhattan, in the county of New York and State of N ew York, have invented certain new and useful Improvements in Processes for Reducing and Desulfurizing Refractory Ores, of which the following is a specification.

This invention relates to the process for desulfurizing refractory ores and separating metals from the fumes generated in the process. The apparatus.

, successive steps ofthis process is claimed in a pair of accompanying applications, namely an application for twyer, .filed Oct. 11th, 1909, Serial No. 521,973, and an application for desulfurizing apparatus for refractory ores, filed Oct. 11th, 1909, Serial No. 521,972.

lVith this invention, refractory ores are heated and cooled for their partial disintegration, and desulfurized with superheated steam, air-and oil. The fumes generated are treated in successive steps to precipitate or separate the metals contained therein. The fumes make consecutive cycles of operations, by matter therein is used in enhancing the steps of the process, and insures the completeseparation of the metals from the fumes.

The metals which are carried off with the i fumes are those wh1ch exist in the ore as minerals, which are volatile at the tempera ture at which the furnace is operated (be' tween-000 to 900 C.) These minerals in the case of gold and silver are the tellurids and selenids especially. Some of the more commonly occurring of these are white tellurium, petzite, sylvanite, nagyagite' and hessite. Other minerals from which silver is volatiliz'ed at a comparativelylow temperature are freieslebenite, polybasite, stephanite, pyrargyrite and proustite. The temperature at which these minerals are volatilized depends upon the conditions under which the furnace is working, such as the quantity of air and steam and their rate of flow, etc;

In the accompanying two sheets of draw- 1ngs,-sect1onal elevations of apparatus with portionsthereof in full lines, are shown to carry out the steps of the process. Y Figure 1, shows a furnace with its twyers,

for carrying out thewhich any combustible Specification of Letters Patent. Patented Jan. 24, 1911. Application filed October 11, 1909. Serial No. 521,974

cooling hopper, baflie box and their appurtenances, and Fig. 2, shows spray tanks, zinc lboxes, an exhauster, a sumpjtank, an oil tank and their appurtenances.

An ore charging hopper is represented at 30, having the upper, sliding gate 33 controlled by the operating lever 40, and the the lever 5 head ofthe water jacketed inclosed furnace 6U; 'Fume piping-64 encircles the head of the furnace and is connected with the interior thereof. Water jacketed twyer supports 68 are connected with the furnace and support the twyers to be described. prevent the ove heating of the walls of the furnace by the said twyers'.

The lower end of the furnace is supported on a frame 76 which has connected up therewith the inclined stationary and discharging chutes 77, and the adjustable chutes 7 S which 1 latter are inclined to different positions by means of the screw rods 79.

Framing 85 supports a cooling hopper 86 having the iii-- let piping S7, and outlet piping 88 located below the furnace. The chutes 77 and 78 lead charges of gangue and metal into the said cooling hopper. v

In the t-wyer supports 68 are located the twyers each with the outer barrel 90 and the forming the annular superheating chamber 132 between them. A fuel chamber 103 extends into each twyer and is threaded on its outersurface for an adjustable damper 104, which latter controls the Volume of air drawn into the twyer to support. combustion therein. Fuel gas inlet piping 105 is connected to each fuel chamber 103 to furnish fuel for each twyer from the oil tankto be described. A burner 110 has connected thereto the steam piping 120, and. the oil piping 122 connecting with said oil oil to start the operations of the twyers, and to combine with the fuel gas from said oil tank to feed the twyers and assist in desulfurizing the ore in the furnace. Steam piping 130 leads steam to the superheating chamber of each twyer, to be superheated by the heat given out from the combustion chamber 96, before mixing with the latter in the twyer supports 68. A pair of rotating combustion chamber 96, the said elementstank, the steam being used to vaporize the lower sliding gates 50 and 51 controlled by 1 The hopper 30 leads to the They ' for.

discharging drums 145 and 148 are journaled within the cooling hopper 86 and have means connected thereto not shown to rotate them, preferably in opposite directions. An inelosed conveyer runway 158 connects with an opening in'the lower end of the cooling tank 86, and contains a conveyer 198 to convey desulfurized ore and metals from the said cooling tank 86. A water jacketed baiile box 200 connects with the fume piping 64 to separate dust from the fumes and isitself connected with the spray tank 215 by means of the piping 220. The latter is connected with a second spray tank 223 by means of piping 224. Fume piping 228 extends fromthe upper end of the spray tank 228 and connects with the zinc box 236, preferably made of wood, and containing the zinc shavings-242. Drain piping 250 connects with the lower portions of the said spray tanks and the bottom of said zinc box. An exhauster 263 connects with the zinc box to draw fumes from the furnace and through the fume piping 64, bathe box 200, the spray tanks 215, 223 and fume piping 228. A sump tank 264 is connected with the discharge end of the exhauster 263, and the drain piping 250 leads into the lower portion of said sump tank. A zinc box 271 similar to 236, having zinc shavings 278 connects with the lower portion of the sump tank 264 and constitutes an overflow there- Fume piping 285 extends fromthe top of the said sump tank to lead fumes to the box 286, preferably of wood, and containing iron shavings 287. A steam coil 288 within said box is used as a dryer. Fume piping 289 leads from the box 286 and connects with the bottom of the oil tank 294. A pipe296 connected with the piping 289 extends into said tank distance of the upper end thereof. The tank has a gage glass 295 and a hand hole at its lower end with hand hole plate 292. A bonnet 297 of thc'tank has fastened thereto a barrel 298, that extends to about the middle portion thereof and 'incloses the upper portion of the-pipe 296. From tion of the tank- 294 extends the fuel gas piping 306 which connects with the piping 105 of'thetivyers. Oil piping 310 extends from the lower portion of theoiltank 294,

and has connected thereto the pump 812 driven by the motor 313. The piping 816 connects with the oil piping 122 of each of r tomatic discharging furnace.

the burners 110 of the twyers;

The mechanical operations and steps of the process "comprise,

successive ch arging ores, preferably refractory, into the charging hopper 30, and by means of the charging gates the ore descends into the central portion of the furnace 60 and piles up from the chutes 77 and 'Z 8 above the level of the tvvyers. Next the exhauster 263 is started 284, to within a short the upper porr generated in the oil and then oily waste to be ignited is placed Within the twyers, and the operations of each tWy'er being the same the description willbe confined to one. Oil is admitted into the twyer by means of the oil piping 122 and steam by means The motor 313 rotating draws the oil from the tank 294 through andinto the piping 310 and 1.22 discharging the same into the twyer. The oil is vaporized by the steam, ignited in the twyer, and is consumed in the combus tion chamber 96. While the vaporized oil is burning in the said combustion chamber, steam is admitted to the annular superheating chamber 132 by means of the piping 180,

and the heat of combustion superheats said steam. When the charges enter the twyer they mix with said superheat While the charge of steam andyaporized-oil is entering the twyer, air is supports 68, ed steam.

drawn therein, and the column thereof is regulated by the damper 104. The desulfurization of the ore is brought about by the action of the superheated steam and air the endothermic reaction of the steam preof the ore, and the volaventing the fusing tile compounds rise as fumes in the furnace. The heat given to the ores in the furnace partially disintegrates them.

While the furnace is being charged with ores the discharging drums 145 and 148 are rotated in opposite directionsto each other. When the ore drops into the cooling hopper 86 it is again disintegrated, and any free metal in the .ore passes With it into said hopper and can be easily separated from the gan e. The

gangue with said free metal is carried awayby means of the conveyer 198. The fumes are drawn up in the furnace 60 by virtue of the action of the exhauster 263 and the intervening appurtenances. After the twyers have-been started by means of the steam from the piping 120 and the oil from the piping 122, and after a portion of the ore has been desulfui'ized, both may be shut off, depending upon the nature of the ore, and the twyers operated by means of fuel gas tank 294, and from the combustible gases generated in the furnace after they have made a cycle (fl-their oper- ,ations and have returned to the furnace.

While the furnace is in operation the discharging drums 145 and 148 are rotated at a speed necessary to discharge the ore at a proper rate for treatment, securing an aufumes leave the furnace they first enter the fume piping 64 and from thence are drawn into the bafile box 200, where the dusty is separated therefrom. The dust enters the outlets 212 and escapes by way of the pipes 218. The fumes are somewhat cooled in said battle box and next enter the spray tank 215 where they are mixed with sprays of the. piping 120;

After the over with the fumes is drawn oli by the 4 tanks.

shavings. The steam ized oil is used as fuel the tank; the remainder of the fumes withthe gases next enters the second spray tank 223 where a further portion of the fumes is collected in the same manner.

T e collected fumes in the form. of a dge are removed from the spray tanks through the openings having the hand hole plates 208 and 222. The uncollected fumes and gases leave the spray tank through the fume piping 228 and enter the zinc box 236. The zinc shavings 242 in the box cause a further separation of the metals fron'i-the fumes and they are deposited thereon. After the completion of the treatment of the charge. in the furnace the zinc shavingswith their deposited metals are removed and separated, after which fresh zinc shavings are placed into the zinc box. The water carried piping 250 which latter also drains the spray The remaining fumes and gases are next drawn into the exhauster 2G3 and from thence dischargeinto the sump tank 264-, the piping 250 leading the water drained from the spray tank 215, 223 and the zinc box 236 into the lower portion of said sump tank. The water carried with the fumes and the gases is separated in the sump tank by gravitation, and in order to collect any metals either in suspension as condensed fumes or in solution the water collected in said sunrp tank is led to the zinc box 271 where the metal and the condensed fumes are collected and deposited on the zinc shavings 27 8 from which the metals are afterwards recovered by the usual methods.- The remaining uncollected fumes and gases in thesump tank rise in the piping 285 and enter the box 286 with the iron shavings 287, in which a further recovery of the metals in the fumes is obtained by their precipitation on the iron pipin 288 in the box 286 dries the fumes. The remaining fumes and gases next enter the oil tank 294 through the piping 289 and the pipe 2J6 rising in the latter. After the fumes leave the 296tl1ey descend into the'barrel 298 and come n contact with the oil in said tank 294 and vaporize some thereof. The vaporgas for the twyers. Metals carried along with the fumes into the oil tank. are filtered by the oil therein and deposited on the bottom of said tank from which they are removed, through theopen- ,ing having the hand hole plate 292. The gases and vaporized oil leave the oil tank 294 by way of the piping 306, after which they enter the fuel gas inlet piping 105. The latter leads-them into the and from which they enter the twyers.

The'reactions which occur in the furnace with the superheated steam and oil when pipe fuel chamber 108 &

there is ample air supply for conducting roasting may be represented as follows:

i t: i HZZ lOtH O; +X a 21(H OHJOQLO -ol(()). If the steam supply is cut oil, then the oil is consumed with the production of very high temperature according to the equation. C l-l +3l(()):1l(l*l ())+l()(CO The effect of the super-limited steam is the prevention of very high temperature as the result of ts endothermic reaction that is the absorption of heat in order to bring about reaction. with the sulfids of the orc,'renmv1ng sulfur according to the equation.

3lieS. .-l5 (H O) :SH S-I-S (F60) +S(). The above reaction occurs when no air is present;'l ut when air is present, as 1n the case when roasting an ore in the furnace the reaction is 3Fci;'. (11 0) +1 5 (0) 1 SFeO-l-S (H O) +6S\.). The metals which collect in the bathe b'ox spray chambers and in the zinc boxes are the metals which are volatillzed, the heavier particles tending to collect in the halite box, the lOSS llHlVHfl' being carried along and a part collected in the spray chambers, and whatis not collected is caught in the zinc boxes. The metallic zinc not only collects the metal particles by filtration but also by chemical precipitation. The latter is the result of some of the volatile minerals being soluble in dilute H 80. and H 80 Which is formed by 550 and SO... taken into solution in the spray chamber. lVhen these solutions The superl'ieated steam also reacts are passed through the zinc boxes; what metal is in solution is precipitated according to the equations, in. which M designates metals MSO +Zn:M+ZnSO MSO +Z 1L-M+ZnSO A general equation for the reactions on sulfid ores in the furnace when acted upon by the superheated steam and no air may be represented by the following 3 (IVES) +3 (11 0) :3MO+3I-L ,S and when both superheated steam and air act on the sulfid ores in the furnace the following equation represents the reaction )r J))+ (H2 2)- The, reaction of the iron shavings on the fumes may be represented by the equations MSO +Fe:M+FeSO lvlSQ-l-FezM-tFeSO in which M designates the metal in combination with SQ; and S0 Having described my invention what Ideshe to secure by Letters Patent and claim is: ,1. The herein described process for desul furizing ores containing vola ile minerals consisting in heating them to partially disintegrate the same, subjecting them to superheated steam and oil for their desulfuriza tion and separating metals from the fumes generated. I 2. The herein described process for desulfurizing ores containin volatile minerals consisting in heating a e orestopartially disintegrate them, subjecting them to super-,

heated steam, oil and air for their desulfuri- '15 zation, separating metals from the fumes generated, and disintegrating the gangue produced. I j

3. The herein described process for desulfurizing ores containing volatile minerals consisting in heating them fort-he partial disintegration thereof, subjecting them to superheated steam, oil and air for desulfurization and dissolving the fumes generated in water, resulting from the generation of sulfurous and sulfuric acids when heating the'ores.

4. The herein described process for desulfurizing ores consisting in heating them for the partial disintegration thereof, and there- '30 by liberating sulfurous and sulfuric acids,

' subjecting the ores to superheated steam, air

and oil to desulfurize them, treating the fumes generated with water thereby forming H sO 'and H and dissolving the min- 35 erals in the solution, subjecting the solution to zinc to precipitate the metals carried over in the fumes and forming zinc sulfite and zinc sulfates;

5. Theherein described process for desul- 4:0 furizing ores containing volatile minerals consisting in heating them for the partial disintegration thereof, and liberating SO 6. Theherein described process for desulfurizing ores containing Volatile minerals consisting in heating them for .the partial disintegration thereof, subjecting the ores to steam, air and oil to desulfurize them, treat-, ing the fumes generated with water to separate metals contained in them, subjectji g the fumes to zinc for the further separatibn of the metals, then treating the fumeswith iron.

to again separate metals therefrom, and treating the fumes with oil to filter remaining metals therefrom, forcing the fumes through an oil tank to mechanically filter any metals carried therein. V

7. The herein described process for desulfurizing ores containing volatile minerals consisting inheating them for the partial disintegration thereof ,,treat'ing the ores with steam and air to desnlfurize them, treating the fumes generated With water to separate metals contained in the fumes, subjecting the fumes to zinc for the further separation of metals in the fumes, treating the fumes with iron to again separate metals there-' from, and subjecting the fumes to oil to filter the remaining metals therefrom and to generate fuel gas for the reduction of the ores.

8. The herein described process for oxidizing 'and desulfurizingore containing volatile minerals consisting in superheating' steam, and mixing itwith vaporized oil and subjectingtheore to the mixture to desulfurize the same, treating the fumes generatcd with water to separate metals therefrom, then treating the fumes with zinc shavings 9 further separate. the metals therefrom'Jnext subjecting the fumes to "iron 99 shavings to againseparate-metals and bringing the fumes in ontact with oil to filter remaining metals herefrom and to vaporize the oil to produce fuel gas for the reduction and S0,, subjecting the ores to steam, oil of ores, and disintegrating the gangue of and air to--desulfurize them, treating the 45 fumes generated with water, thereby forming H SO and H 80, and dissolvingv the j soluble metals contained in the fumes in said York this 9th day of October A. D. 1909,

' solution, treating the solution'with metallic zinc toprecipitate the metals thereof an precipitate remaining metals from the fumes.

CHARLES ANDERSON-CASE Witnesses:

A. A. on Bonnnvrnnn, MARTIN ZIMANSKY. 

